Which of the following solutions has the highest $pH = 14$?

The $pH$ of $10^{-5} \ M$ aqueous solution of $NaOH$ is

$pH$ value of $0.001 \ M \ NaOH$ solution is $..... .$

At $27^{\circ} C$,$100 \ mL$ of $0.5 \ M$ $HCl$ is mixed with $100 \ mL$ of $0.4 \ M$ $NaOH$ solution. To this resultant solution,$800 \ mL$ of distilled water is added. What is the $pH$ of the final solution?

The $pH$ of a $10^{-10} \ M \ NaOH$ solution is nearest to

Calculate the $pOH$ of $0.10 \ M \ HCl$ solution.